Method of relining cannon.



nerf at Watervliet senal ement.. n-.MethQd 'f which t methods have vfailjed.. The intense lheat of wder Y gasesl following thepr'ojeetile the bore to 'expand and the thin liner 1s -heatedto a muchV higher teinperatui'e,'y and 0 therefore :expands more he tube.'A "As the hot 'gases sweep ube ieools more rapidly than the liner,y and c ntracting, gripsthey inetalfofthe liner. This prevents themetaljof the linerwhich s exp urning. *toit's-o1 "iginal positions, as,fwheni eflinernoools thefeontraction' of*y the tube lds. the endsi and-1 the liner then stretches; l

/be'conngphinein mammie; The liner is 50ffal`so stretohedfby ymandielingg;` of the shell,l

ywhich causes movement of the vrnetal toward the nozzle. v This stretching recours s' when than they mass of'v by they- 'their sent ,int-0. the Held fior' use, ui

diem! eresiol. 71S ell Thisy has beenwproven b rorneAv of, inventions' thev hner is4 pressed' placey inthe. tube and fing, 'therebyv eliminating the` shrinkage @per` f ationof other'y methods. 1

This allows thecomplete finishing i i .I''lng of the liner before insertion into the tube',-where`as,l in .ktheir'sgolder methods usingv f shrinkage, the liners v ufstf be I'illed'y *after it inplace inthe tubedue to the distortion a :injurious eectsofheat'ing. Theiniport and advantag sofgbeingjable toA lineifbefore it e 1s "plaeedl l'in posit gun willy be obvious@ This allows l11n nished at a proper-,ly equipped 'base a hating the necessity of returningfzaseannon to the base for relining. AVA saving vof 'fully sev' enty pei'- centLinthe'time neeessai r torelin av gun isthus eiectedby' thismet thenseeuredbywel elirniif hich the temperature rise even is the only one known permitting the complete finishing and rifiing of liners before insertion into, thetube. Although the method of welding 'may 'also be vapplied where the shrinkage operation is usedL the additional advantages obtained through securing the liner without resorting to the injurious heating of the-"shrinkage operation will beiiapparent to one skilled in the-art. Inthe welding operation the heat is applied locally and -close-to lthe weld 1s entirely negligible.

-Theobject `Vand''advantages 'of this inveny tion are attained by-applying thei'nethod as shown i'n a preferred form in the accom` panying drawing in which:

Figure 13, lisa view of a 'cannon partially broken Vaway* 'showing `the breech and Amuzzleendsin section.

v Fig. 2, 'is a fragmental section of the breech end. l

Fig. 3, is a fraginental section of the muzzle end. l

'In thedrawing 'l is "the jacket' vof a cannOn and is the tube. Liner 3 is preferably pressedfinto Vposition in tube l2,bu`t'shrinka"ge can be used. Annular groovec 'is -,turned partially in theftube end partially :intlie liner as shown; Groove'l vis then filled with metal 5byfth'e electricwelding process thereby joiningthetube andlinersecurely. The surface isthenproperlymachined` In a like manner groove is turned" in 4the muzzle endand. filledl with metal l.

To reline, tliewveldedinetal portions 'are bored out, 'the old liner f canthen fbe forcedr outand easily replaced bya new liner. eliminates tl'ieexcessive wear on the tube due to "the jmeans necessary *in removing liners securedr by the'older'method's andjtli'e life' of 'the cannon 'is therefore greatlyv infcreased. l Y 4 d, ,l v

While electric welding is the preferred f i means forsecuring the liner 1n place, 1t 1s to be understood` that any form of Welding 'or permanently securing tlieliner in place and against creeping may be resorted to withoutgdeparting from the scope of the invention. f

Having shown and described an embodiment of the preferred form of iny invention, I claim:

l. The method of securing semifinished liners 4iii-cannon by welding. 2. The method of securing nished an rifled liners in cannon by welding at 'the breech end.

3. The method of securing finished and riled liners Ain cannon by welding at the muzzle end. l

4. The method of securing finished and rifled liners Vin cannon by' welcling"at"the breech and muzzle ends. d

5. The method= of securing 'liners in cannon b a welding heat'locally applied.

6. 'yhe method' ofsecuring liners in cannon by electric welding.

7. The method'ofsecuring liners in'can-V non, which consists in first placing the liner, in an unheated condition, in thecannon, and thenapplying a welding heat to 'weld `the same to the cannon,

8. The 'method of securing "liners in cannon, which consists in first lpressing lthe liner into place inthe cannon tube, and" then applying a 'welding heat to weld the liner to the tube.

9. The methodfofsecuring liners'in c'anf non, which consists linii'rst placing the Alliner, in a'n unlieat'ed condition, in the'cannon, and then applying a welding heatlocalizedina certain area or"zone"of"the liner, to :weldthe 'liner to 'the cannon. l Y

cannon provided Vwltli a liner Copies of this patent may be olitainedor lve cents each, by addressing `theConi'n'i'issiiine'rf atei'ts;

Washington, 1); C. 

